Mini-subvastus versus medial parapatellar approach in total knee arthroplasty.

UNLABELLED: We compared short-term clinical results of the mini-subvastus approach with the standard parapatellar approach for total knee arthroplasty. Can one gain adequate access through the mini-subvastus approach without exceeding operating time, incurring additional complications, and maintaining correct implant geometry? In a prospective, observer-blinded study, 120 consecutive patients having total knee arthroplasty were operated on by one surgeon using either the mini-subvastus approach without patella eversion or the standard parapatellar approach with patella eversion. Patients were matched according to age, gender, body mass index, knee flexion, deformity, and pre-existing high tibial osteotomy. The mini-subvastus approach was technically more demanding. Reduced access and visibility prolonged the tourniquet time by an average of 15 minutes and led to two intraoperative complications. Patients in the mini-subvastus group lost on average 100 mL less blood and had better pain scores on day one [visual analogue scale (VAS): mean 2.4 versus 3.89]. They reached 90 degrees knee flexion earlier (2.8 versus 4.5 days), and an active straight-leg raise earlier (3.2 versus 4.1 days). Their average flexion at 30, 60 and 90 days was slightly better (100 degrees , 110 degrees , and 112 degrees versus 94 degrees , 106 degrees , and 109 degrees ). All patients including those with complications had good results with good component geometry and leg alignment. The mini-subvastus approach offers early but short-lived benefits for patients at the expense of a longer operation and a higher risk of complications. LEVEL OF EVIDENCE: Therapeutic study, Level II-1 (prospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Measurement of canal occlusion during the thoracolumbar burst fracture process.

Post-injury CT scans are often used following burst fracture trauma as an indication for decompressive surgery. Literature suggests, however, that there is little correlation between the observed fragment position and the level of neurological injury or recovery. Several studies have aimed to establish the processes that occur during the fracture using indirect methods such as pressure measurements and pre/post impact CT scans. The purpose of this study was to develop a direct method of measuring spinal canal occlusion during a simulated burst fracture by using a high-speed video technique. The fractures were produced by dropping a mass from a measured height onto three-vertebra bovine specimens in a custom-built rig. The specimens were constrained to deform only in the impact direction such that pure compression fractures were generated. The spinal cord was removed prior to testing and the video system set up to film the inside of the spinal canal during the impact. A second camera was used to film the outside of the specimen to observe possible buckling during impact. The video images were analysed to determine how the cross-sectional area of the spinal canal changed during the event. The images clearly showed a fragment of bone being projected from the vertebral body into the spinal canal and recoiling to the final resting position. To validate the results, CT scans were taken pre- and post-impact and the percentage canal occlusion was calculated. There was good agreement between the final canal occlusion measured from the video images and the CT scans.

Does 'canal clearance' affect neurological outcome after thoracolumbar burst fractures?

Surgical decompression of the spinal canal is presently accepted worldwide as the method of treatment for thoracolumbar burst fractures with neurological deficit in the belief that neurological recovery may be produced or enhanced. Our clinical and laboratory experience, however, indicates that the paralysis occurs at the moment of injury and is not related to the position of the fragments of the fracture on subsequent imaging. Since the preoperative geometry of the fracture may be of no relevance, our hypothesis, backed by more than two decades of operative experience, is that alteration of the canal by 'surgical clearance' does not affect the neurological outcome. We have reviewed the existing world literature in an attempt to find evidence-based justification for the variety of surgical procedures used in the management of these fractures. We retrieved 275 publications on the management of burst fractures of which 60 met minimal inclusion criteria and were analysed more closely. Only three papers were prospective studies; the remainder were retrospective descriptive analyses. None of the 60 articles included control groups. The design of nine studies was sufficiently similar to allow pooling of their results, which failed to establish a significant advantage of surgical over non-surgical treatment as regards neurological improvement. Significant complications were reported in 75% of papers, including neurological deterioration. Surgical treatment for burst fracture in the belief that neurological improvement can be achieved is not justified, although surgery may still occasionally be indicated for structural reasons. This information should not be withheld from the patients.

Is routine removal of intramedullary nails justified.

This study investigates the outcome of 100 cases of lower limb intramedullary nail removal. 12 femoral and 25 tibial nails were removed for pain and 4 tibial nails for infection. For 22 tibial nails and 38 femoral nails there was no recorded indication. There where 3 operative complications, 2 abandoned procedures and 1 tibial fracture (nail extraction without prior removal of the distal locking screw). In 9 out of 16 cases anterior knee pain improved after tibial nail removal. 4 patients, previously asymptomatic, developed anterior knee pain following tibial nail removal. 40 patients who were discharged without crutches returned in pain and had to be given crutches to alleviate leg pain. 62 patients took a mean of 11 days sick leave. We conclude that all complications were avoidable. Intramedullary nail removal is safe. Patients with anterior knee pain should be told that their pain may persist and that knee pain may even arise. Most patients will require crutches and an average of 2 weeks away from work.